Concentric grinding unit for use on surface grinders and the like



J. R. EVANS J l zs, 1952 CONCENTRIC GRINDING UNIT FOR USE ON SURFACE GR'INDERS AND THE LIKE FiledMay 29, .1950

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Patented July 29, 1952 CONCENTRIC GRINDING UNIT FOR USE ON SURFACE GRINDERS AND THE LIKE John Robert Evans, Moi-den, England Application May 29, 1950, Serial No. 164,920 In Great Britain May 30,1949 7 This invention relates toa device for grinding cylindrical components.

The main object-of the invention is to bring to engineering workshops a speedy and cheap means of obtaining many high class ground components, such as press tool piercing punches, plug gauges, D-bits, drill jig bushes, special reamers, counterbores and the like, where a costly universal grinder is not available, but such means which gives the facility of accurate centering in a simple manner, thereby relieving bottlenecks in production and providing for relief in workshops where a universal grinder is installed but loaded to capacity with work. I

The device provided by the invention is constructed as a portable unit for holding the component to be ground in appropriate position for accurate grinding by a conventional grindenbut which if so desired can be built into a small selfcontained grinding machine so that its usefulness can be extended to the smaller type of workshop where grinding equipment is limited or has no work feeding facilities.

According to the invention there is provided a grinding unit for concentric grinding of cylindrical components comprising a work holder having a U-channel for locating the component, resilient pressure applying means for rotatably holding the component in the channel and means for rotating the component in the channel. 1

Preferably, the pressure applying means is a bar which is pivotally mounted between its ends 7 so as to lie at right angles to the V-channel, one

end of the bar lying over the channel and the opposite end being acted upon by a spring which causes the component engaging end to pass resiliently on to a component located in the channel.

According to a simple construction, the work holder is a rectangular block which is capable of being held by the magnetic or other chuck or on the cross slide of a grinding machine, said block having the V-channel extending transversely between opposite sides and adjacent one end thereof and a socket formed towards the opposite end to receive a coil spring and plug which presses against the underside of the pressure bar. the bar pivot being disposed between the socket and the channel and being formed by a screw which screws into the work holder to provide for vertical adjustment of the pivot in relation to the work holder.

In order that the invention may be readily understood and carried into effect reference will 2 Claims. (01. 51-236) 2 7 now be made to the accompanying drawing which shows a simple unit construction, and in which:

Figure l is a general pictorial view of the unit for application'to the chuck or worktable of a grinding machine,

Figures 2 and 3 show in side and front elevation respectively the pressure bar incorporated in the unit,

Figure 4 is a vertical longitudinal section through the unit,

Figures 5 and 6 are side and front elevations of the handwheel for rotating the component in the work holder of the unit,

Figure 7 shows a typical component mounted in the handwheel,

Figure 8 shows a composite component which can be ground by the use of the unit and Figure 9 shows in side elevation the unit in operative position with a grinding wheel.

As shown, the unit comprises a rectangular work holder block I of hardened steel across the top face and adjacent one end of which extends between and square with opposite sides a V- channel 2 in which may be seated and located the component, such as 3 or 4 (Figures 7, 8, 9) to be ground. The component is held in the V- channel by the lipped end 5 of a pivotal pressure bar 6 which is mounted longitudinally of the block at right angles to the V-channel by means of a screw 1 the head 8 of which forms the pivot for the bar and which screws into the top face of the block to provide for vertical adjustment of the pivot and thereby adjustment of the lip 5 of the pressure bar relative to the V- channel to provide for engagement of a range of components of different diameters, The shank of the screw I passes through a hole 9 drilled intermediately between the ends of the pressure bar 6 and in line with a recess IE on the underside of the bar disposed towards the outer end ll of the bar which overhangs the end of the work holder block remote from the V-channel 2 so that the pressure bar can be conveniently depressed by an operator to rock about its pivot point 8 and thus lift the component engagement end 5 clear of the V-channel. In vertical alignment with the recess in in the pressure bar, a socket I2 is formed in the work holder block I, which socket houses a coil spring l3 and a plug [4, the head of which engages in the bar recess i0, the plug being located by a spigot l5 of reduced diameter inserted into the end of the spring. The component to be ground, such as 3 or 4. is laid in the V-channel, after first depressing the hand engaging end H of the bar 6 which extends beyond the end of the block opposite the channel to lift the lip 5 clear of the channel, and the bar is then released, whereupon the spring pressing upwardly under the end H through the plug it, causes the lipped end 5 to engage the component with a pressure sufficient to locate it accurately seated in. the V while permitting the component to be rotated while it is being ground. The distance between the pivot head 8 of the screw bearing against the periphery of the opening 9 and plug l4 engagingin recess I0 is greater than the distance between the lip.

5 and opening 9 in order to insure that a jolt ot considerable magnitude is necessary to-disturb the component in the V-channel while; at: the

same time the tail portion l l of the bargfi which projects beyond the block in its relation to 8-9 reduces the downward pressure necessary to raise the lipped end of the bar.

For the purpose of rotating the component,. a suitable handle isprovided, which-conveniently: takes the form of a handwheel 16 having an-iirtegralcentre boss: H in whichv the end; ofv the component can be inserted, anda devices for: se.-.

curing the component in the bush,.which. device: inthe simple form shown consists of. grub; screws |8=each mounted in one of three. equiangularly. spaced tappings 19 extending radially-from; the. centre boss I1 to the periphery of the wheeli.

The unit with the component. 3, which is. a

typical punch, in position; isshownain figure held down onto-the table 20 0f: atgrindingamw chine, with the component end; which; is. to* be.- worked upon, engaged by the grinding .wheel. 2| of the machine. While the grindingwheelroe tates, the component is also rotatediby the operator rotating the handwheel using: the handle- 22ithereon, the grinding wheel. being; fed down until the desired diameter: is; obtained; the result isuconcentric to the axis. of, the component due' to the location. of; the V,-channel andthe; pressure banwhile the component is rotated'beftween them;

The; grinding. machine may include any usual means .such as. a magnetic chuck for holding down theworkholderand will include thenormal cross-1 slide;- by which the;.holderi I- may be traversed relatively to the grinding wheel in ac.- cordance with. the, lengthtofi the ground diameter required;

Bushes and. sleeves maybe readily ground in a. similar manner by the employment of the mandrel 4..- (Figure 8')- which may have previously been ground by meansofthe unit, on toone end; of which the bush or sleeve is fitted, the. other; end of themandrel being; securedin the. boss l'l'of the hand wheel-l6.

The unit according. to the. invention-fmaybe built into a self-contained bench or stand. ma.-

chine, by includingthe-work holder aspart of as frame which carries a. grinding wheel, means be.

ing provided-for traversing. and downward feed-'4 ingot. the holder or the wheel, and .anelec'tric motor preferably being, incorporated .in the. ma: chine for. drivingthe. wheel I claim:

1. A grinding unit for concentric grinding of cylindrical components, comprising, in combination, a work holder block having a V-channel at one end across its upper face for locating a work component and also having a vertically disposed medially located threaded hole and a vertically opening socket adjacent the end" opposite't'hechannel, a pressure bar having a downward component engaging lip at one end located over the channel and having an intermediate opening for receiving the shank of a screw adiustablyt fitted in said threaded hole, the head of said screw constituting a pivot for the bar,

said: bar having a recess in its underside and also havinga rearwardly extending hand engagingtail portion extending beyond the end of the block opposite the channel, a spring pressed plug insaid socket and bearing in the recess in the underside of the bar between the terminus of itstail portiorr. andthe head ofthe screwi which forms the pivot, the distance: between fthe plugiand; the. head of. thescrew being greater than the distance between: the lip and the head of the 1 screw to provide: leverage. to". tightly hold: thecomponent: in the V-channel. while the extendect length of. the-:tail portion of the bari provides: 9/; hand engaging. portion beyond; the' plug and: sufficiently remote from. the head: of the screw:- to reduceathe; manual pressure necessary: to raise thedip; end-.oflthe bartorelease thecomp'one'nt;

2. A grindingunit; for. concentric" grinding of cylindrical-workpieces. comprising; in combination, a Workholderrconsisting of a rectangular block havinga. V-channe1 extending transverselybetween aopposite sidesiand adjacent one end thereof. and; a. socket; formed towards the end thereof. remote; fromasaid channel, a handwheel adapted-tube mounted: onai workpiece positionedin:. said channel; a screw' threaded into said block betweensaid channel and saidsocket, a-

pressureban pivotally' mounted-"between: itsends on said screw and located;at.right"ang-les to said channeL. one. end: of. said bar lying"; oversaid channel and beingformedw-itha vertical lip cen trally. disposedwith. respect toand directed towards: said. channel, and .a plug and coil-springlocated within; said; socket; said plug being pressedrby. said springagainst said pressurebarwhereby. said. lip: is pressed into contact with said workpiece. Y JOHNROBERT-EVANS. I

REFERENCES CITED The following references are of record in the file ofi this patent:

UNITED STATESQPATENTS;

Davis Nov. 14, 1939 

